Apparatus for supplying descaling installations and the like with a flow of low or high pressure fluid



Feb. 17, 1970 H. w. HEROLD 3,

APPARATUS FOR SUPPLYING DESCALING INSTALLATIONS AND THE LIKE H WITH A FLOW 0F LOW 0R HIGH PRESSURE FLUID Filed May 24, 1966 3 Sheets-Sheet 1 FIG. I

Feb. 17, 1970 w, HEROLD 3,495,613

APPARATUS FOR SUPPLYING DESCALING INSTALLATIONS AND THE LIKE WITH A FLOW OF LOW OR HIGH PRESSURE FLUID Faled May 24, 1966 3 Sheets-Sheet 2 Feb. 17, 1970 H. w. HEROLD 3,495,613

APPARATUS FOR SUPPLYING DESCALING INSTALLATIONS AND THE LIKE WITH A FLOW OF LOW OR HIGH PRESSURE FLUID Filed May 24, 1966 3 Sheets-Sheet 3 7 1 [mu 1 5| 5 l 7 I 3 United States Patent 3 495 613 APPARATUS FOR SIlPPLYING DESCALING IN- STALLATIONS AND THE LIKE WITH A FLOW OF LOW OR HIGH PRESSURE FLUID Hans Wilhelm Herold, Kongen, Baden-Wurttemberg,

Germany, assignor to Werner & Pfleiderer, Stuttgart- Feuerbach, Germany Filed May 24, 1966, Ser. No. 552,546

Claims priority, applica tiog Germany, May 28, 1965,

34 Int. Cl. F16k 11/02,- E03d 3/10;F11d 1/00 U.S. Cl. 137625.4 5 Claims ABSTRACT OF THE DISCLOSURE The invention relates to an apparatus for supplying descaling installations and the like with a flow of low or high pressure fluid issuing from spray nozzles arranged on platforms.

Various hydraulic installations for rapid and effective descaling are used for the descaling of workpieces in hot rolling mills as well as in forging works. The installations includes platforms having nozzles which during the descaling processes are supplied with a flow of high pressure liquid which issues from the separate nozzles and impinges at high pressure on the work-piece to be descaled. In a known installation of this type, the nozzle platforms are supplied, during the intervals of spraying, with a low pressure liquid to avoid air inclusions inside the nozzles or the nozzle platforms and the associated fluid circuit, as otherwise, on subsequent actuation of the flow of high pressure fluid, damage could occur inside the installation. In this arrangement, the low pressure side is shut off from the high pressure side by a non-return valve which is kept closed by the actuated flow of high pressure liquid.

It has been found that the arrangement of such nonreturn valves in separate low pressure flow circuits connected to the nozzle platforms can be disadvantageous. This is due in part to the known susceptibility to trouble of the non-return valves per se. For instance, it is not always possible to select a position for the mounting of the non-return valves such that a jamming can be reliably avoided, and this is particularly true when corrosion influences or impurities in the low pressure fluid assume significance.

In all cases in which reliable working of the non-return valve is not ensured, a part of the high pressure stream flows into the low pressure stream circuit which can lead to disturbances in operation and damage to the installation. This additionally causes a loss energy, which has an unfavorable eifect on the economical working of the installation as a whole.

The object of the invention is to avoid the abovementioned disadvantages and to provide an apparatus which ensures a positive and sure separation of the high and low pressure flow circuits and at the same time avoid the sources of breakdown resulting from the use of non-return valves acting adversely as regards the high pressure flow.

3,495,613 Patented Feb. 17, 1970 ice This object of the invention is attained essentially by means of a control valve with a displaceable piston, in which the housing is provided with high and low pressure areas admitting low or high pressure fluid, with at least one such area admitting pressure fluid in such a way that the piston is displaced to open or close the low or high pressure side respectively. There is accordingly positive control of the high and low pressure fluid, and assurance is given that on drop-out of the high pressure flow, or possibly the low pressure flow, or a reduction of the pressures existing in the circuits below a given minimum value, the control valve will automatically block the corresponding circuit. In every case injurious air inclusions and the disadvantages occasional by other sources of failure are reliably eliminated, and damage to the interior of the installation is positively avoided.

The invention provides that the bearing-surface areas of the piston are arranged to act in opposition to each other, with the sum of the forces acting on the surfaces arranged in the same pressure direction being greater than the sum of the forces acting on the surfaces of the piston arranged in the opposite pressure direction. By this means it is possible in a simple way to adapt the control valve to given operating conditions, such as for instance by appropriate dimensioning of the high pressure flow which effects the displacement of the piston, or of the surfaces admitting this fluid.

In accordance with another arrangement of the invention, the inlet opening for the low and high pressure fluids can be arranged in each case at an end of the control valve housing and the piston at both ends provided with sealing sections of different size so as to make it possible for the one liquid flow circuit to open only after the other circuit has closed. This can be effected simply such as by covering the two end sealing sections of the piston, which at the same time can be provided with conical seatings for cooperation with corresponding seatings in the housing and by the dampening effect thereof on actuation of the control valve prevent the occurrence of hydraulic impacts and other disadvantages, such asv increased wear and tear.

The piston of the control valve is formed longitudinal channels, one of which channels, when the low pressure connecting pipe is opened, effects a connection to a pipe connected to the housing and leading to the platforms, while another channel thereof connects the high pressure side of the housing continuously with a pressure chamber provided in the housing, with the pressure chamber enclosing one of the bearing surfaces of the piston.

The displacement of the piston is effected by an area of the piston admitting pressure fluid, with the pressure fluid being supplied via an externally controlled valve and the corresponding bearing surface area remaining pressureless or admitting high pressure fluid in accordance with the position of the valve at the time. The pressure fluid can be tapped either from the high pressure stream flowing into the housing or supplied via an independent control pipe for the high pressure fluid flow.

As already mentioned, the position of the valve concerned is determined by an externally controlled pressureoperated valve, which may be connected with a safety device inserted in the low pressure flow circuit, with the result that on any interruption of the flow of low pressure fluid, the actual control valve is not actuated to activate the high pressure flow circuit.

The invention will now be described with reference to the accompanying diagrammatic drawings, which shows an embodiment of the invention, but in no restrictive sense.

FIGURE 1 is a diagrammatic view in elevation of the descaling apparatus, with two nozzle platforms and control members.

FIGURE 2 is a view in longitudinal section through a control valve of the descaling apparatus of FIGURE 1, shown in working position, and

FIGURE 3 is a view in longitudinal section through the control valve of FIGURE 2, showing a different position of the piston.

A workpiece, for instance a rolled or forged piece 4, shown in dotted lines in the drawing, is inserted between an upper platform 2 and a lower platform 3 each of which is equipped with nozzles 1, and is descaled by means of high pressure jets of fluid issuing from the nozzles 1.

The platforms 2, 3 are supplied with high pressure fluid via guide pipes 5, 5', which are fed from a high pressure pipe 7 attached to a control valve 6, shown diagrammatically.

As can be seen from FIGURE 1 of the drawings, the control valve 6 is supplied with a flow of high pressure fluid via a supply pipe 8 with interposed slide valves or some other shut-off member 9 and with a flow of low pressure fluid via a supply line 10 with an inserted shutoff member 11. A further pipe 12 is attached to the control valve 6. The said pipe 12 acts as an actual control pipe and is fed via a valve 13 from a pipe 14 conveying a flow of high pressure fluid. The pipe 14 also is provided with a shut-off member 15'.

The valve 13 is constructed as a 3/2-way valve and is controlled by a preliminary valve 16, which is preferably pressure-actuated and fed via a pressure air pipe 17, shown in dotted lines, with the pressure air pipe having an interposed shut-off member 18.

In FIGURE 2, the control valve 6 is shown in section, with the supply pipes 7, 5, 5' and the nozzle platforms 2, 3 being in elevation. The valve housing including two parts 6, 6" has end flanges 18a and 19 for the connection of the control valve 6 with the high pressure pipe 8 and the low pressure pipe 10 respectively. The fixing of the flanges 18a and 19 can be effected in any desired manner, for instance by means of screws or the like, and the flanges per se can also be of multi-part construction, as can be seen in FIGURE 2, by the arrangement of an additional bushing 18 on the high pressure side. Bores 7' and 12', respectively are provided inside the housing part 6 for the pipe 7 and the high pressure pipe 12 leading to the nozzle platforms 2, 3, and the bores open into corresponding pressure chambers 7" and 25.

A movable piston 20 is accommodated within the valve housing and is provided with substantially cylindrical end sealing sections 21, 22 having conical seating surfaces 21', 22' respectively cooperating with corresponding sealing surfaces of bushings 23, 24 inserted in the housing parts 6', 6". Hence, position of the piston 20 inside the control valve 6, determines whether the high pressure side 8 or the low pressure side 10 is blocked.

When the nozzle platforms 2, 3 are to be supplied with pressure fluid via the pipes 7, 5 and 5 leading from the control valve 6 to the nozzle platforms, the piston 20 assumes the position shown in FIGURE 2, so that the pressure fluid can pass from the high pressure pipe 8 leading to the interior of the control valve 6 into the pressure chamber 7", through the bore 7 into the pipe 7, and via the guide pipes 5, 5 to the nozzle platforms 2, 3 and the nozzles 1.

The position of the piston 20 inside the housing parts 6', 6" is necessarily determined by a flow of high pressure fluid conveyed from the pipe 14 via the valve 13, the pipe 12 and the bore 12' into pressure chamber 25. This is due to the fact that the pressure acting in the direction of the arrow a on a corresponding pressure surface 25' of the piston 20, located within the pressure chamber 25, together with the pressure acting in the direction of the arrow b on the end face of the piston 20 and its sealing section 21, is greater than the flow of high pressure fluid conveyed via longitudinal bores 27 in the piston 20 and corresponding trans-verse bores 28 into a corresponding pressure chamber 26 acting in the direction of the arrow 0 on opposite pressure surface 26' and the pressure of the low pressure flow acting in the direction of the arrow d on the other end of the piston 20 and its sealing section 22. Accordingly, the forces acting in the direction of the arrows a and b are greater than the forces acting in the opposite direction is noted by arrows c and d, and thereby hold the piston 20 in the position shown in FIGURE 2, so that the low pressure pipe 10 is blocked and the nozzles 1 of the platforms 2 and 3 are supplied with spray water.

The extent of the forces acting on the concerned pressure surfaces of the piston 20 can be determined in a simple way by the size of the individual pressure surfaces as a function of the extent of the flow of high or low pressure concerned.

If, on the other hand, the high pressure flow is to be blocked, i.e. the spray action of the nozzles is to be terminated, the valve 13 is opened via the pressure-actuated preliminary valve 16 and the pressure chamber 25 is vented via the pipe 12 and pipe 13" connected to the valve 13. The surface 25' of the piston 20 is relieved of pressure so that the pressure in direction of the arrow a drops to zero. The forces acting in the direction of the arrows c and d thus become greater than the force acting in the direction of the arrow b, and the piston 20 is moved from the position shown in FIGURE 2 into the position illustrated in FIGURE 3 and simultaneously the supply of high pressure fluid through the pipe 8 is positively blocked. Since, on the displacement of the piston 20" fluid is expelled from the sealing sections 21 and 22, a dampening effect is present which ensures a smooth opening and closing of the valve 6.

In order to avoid injurious air inclusions and particularly in the nozzles 1 and platforms 2, 3 or associated pipes 5, 5 and 7, when the closing of the high pressure pipe 8 begins, the low pressure pipe 10 is freed from the sealing section 22 so that the flow of low pressure fluid, acting as feed flow, is conveyed to the pipes 7, 5, 5' and accordingly to the nozzle platforms 2, 3, via a transverse bore 29 in the sealing section 22 facing the low pressure side 10, a further longitudinal bore 30 inside the piston 20 and a transverse bore 31 facing the sealing section 31. The bore 31 opens into the pressure chamber 7", and the pressure chamber is in communication with the bore 7' previously mentioned. The position of the piston 20 is here ensured by the flow of high pressure fluid, acting in the direction of the arrow c via the bores 27, 28, into the pressure chamber 26, as well as by the flow of low pressure fluid, acting in the direction of the arrow d, in the same direction.

When, after the insertion of a fresh work-piece 4, pressure fluid is again to be supplied to the nozzles 1, the valve 13 is actuated via the preliminary valve 16 which is pressure-actuated and supplied via the pressure air pipe 17, so that high pressure fluid flows, via the high pressure pipe 14 and the pipe 12 opening into the control valve, into the pressure chamber 25 and against the pressure surface 25 of the piston 20, whereby the forces directed according to the arrows a and b again become effective, with such forces being greater than the forces acting in the opposite direction as indicated by arrows c and d, so assumes the piston 20 again takes position shown in FIGURE 2.

The pipe 14 leading to the valve 13, is, as can be seen in FIGURES 2 and 3, branched from the flow of high pressure fluid in the pipe 8. It can, however, be fed from another pressure source having a pressure different from the pressure existing in the pipe 8.

The pressure air pipe 17 for controlling the preliminary valve 16 or the shut-off member 18 or the like inserted in the pipe 17 can also be connected with a safety member, installed for instance in the low pressure pipe (not shown) in such a way that on drop-out of the flow of low pressure fluid, the valve 13 freeing the flow of high pressure fluid does not respond.

I claim:

1. An apparatus for descaling installations for selectively supplying high pressure fluid or low pressure fluid to platforms equipped with spray nozzles, comprising a housing, conduit means for providing communication between the interior of the housings and the platform, a control valve having a movable piston positioned in said housing, said housing being provided with means constitutng inlets for high and low pressure fluids and an outlet to said conduit means, said piston being movable between a first position permitting fluid flow from the high pressure inlet to the outlet while preventing low pressure fluid flow, and a second position permitting fluid flow from the low pressure inlet to the outlet while preventing high pressure flow, said piston having a first pressure surface exposed to the high pressure fluid at the high pressure inlet whereby the pressure of the fluid tends to move the piston towards its first position, a second pressure surface exposed to the low pressure fluid at the low pressure inlet whereby the pressure of the fluid tends to move the piston towards its second position, and a third pressure surface, means for controllably applying pressure fluid to the third pressure surface for displacing the piston between its first and second positions, said piston being provided with a fourth pressure surface and longitudinal channels, one of said longitudinal channels being arranged for connecting the low pressure inlet to the conduit means when the piston is in its second position, and to be closed when the piston is in its first position, and another of said channels being arranged for connecting the high pressure inlet permanently with a pressure chamber provided in the housing and enclosing the fourth pressure surface.

2. An apparatus for descaling installations for selectively supplying high pressure fluid or low pressure fluid to platforms equipped with spray nozzles, comprising a housing, conduit means for providing communication between the interior of the housing and the platforms, a control valve having a movable piston positioned in said housing, said housing being provided with means constituting inlets for high and low pressure fluids and an outlet to said conduit means, said piston being movable between a first position permitting fluid flow from the high pressure inlet to the outlet while preventing low pressure fluid flow, and a second position permitting fluid flow from the low pressure inlet to the outlet while preventing high pressure fluid, said piston having a first pressure surface exposed to the high pressure fluid at the high pressure inlet whereby the pressure of the fluid tends to move the piston towards its first position, a second pressure surface exposed to the low pressure fluid at the low pressure inlet whereby the pressure of the fluid tends to move the piston towards its second position, and a third pressure surface, and an externally controlled valve operably related to said piston for supplying pressure fluid to said third pressure surface.

3. The apparatus as claimed in claim 2 in which the pressure fluid conduit is branched from the high pressure inlet and the high pressure fluid acts on the third pressure surface for moving the piston towards its first position.

4. The apparatus as claimed in claim 3 in which said piston is provided with a fourth pressure surface and with longitudinal channels, one of said channels being arranged for connecting the low pressure inlet to the conduit means when the piston is in its second position and to be closed when the piston is in its first position, and another of said channels being arranged for connecting the high pressure inlet permanently with a pressure chamber provided in the housing and enclosing the fourth pressure surface.

5. An apparatus for descaling installations for selectively supplying high pressure fluid or low pressure fluid to platforms equipped with spray nozzles, comprising a housing, conduit means for providing communication between the interior of the housing and the platforms, a control valve having a movable piston positioned in said housing, said housing being provided with means constituting inlets for high and low pressure fluids and an outlet to said conduit means, said piston being movable between a first position permitting fluid flow from the high pressure inlet to the outlet while preventing low pressure flow, and a second position preventing fluid flow from the low pressure inlet to the outlet while preventing high pressure fluid flow, said piston having a first pressure surface exposed to the high pressure fluid at the high pressure inlet whereby the pressure of the fluid tends to move the piston towards its first position, a second pressure surface exposed to the low pressure fluid at the low pressure inlet whereby the pressure of the fluids tends to move the piston towards its second position, and a third pressure surface, and an externally controlled preliminary valve for determining the position of said control valve.

References Cited UNITED STATES PATENTS 449,457 3/1891 Yeo 137112 474,000 5/1892 Dean 137112 831,677 9/1906 Noone 137112 2,729,226 1/1956 Jones 137-112 3,109,454 11/1963 Whitlock et al. 137-62549 3,215,163 11/1965 Henderson 251- X 3,349,800 10/1967 Herion et al. 137625.66

M. CARY NELSON, Primary Examiner MICHAEL 0. STURM, Assistant Examiner US. Cl. X.R. 2512.5 

